Cylinder broach



H. P. PHILLIPS CYLINDER BROACH April 1, 1952 2 SHEETS-SHEET 1 Filed Jan.6, 1947 INVENTOR- /7a/"0/0 A P/91' [/1 5. a 2 ATTORNEY.

H. P. PHILLIPS CYLINDER BROACH 2 SHEETS-SHEET 2 Filed Jan. 6, 1947 a o ZRH M 2 my. W m% 6 a/ a d W j W 9 k\ x N ATTORNEY Patented Apr. 1, 1952CYLINDER BROACH Harold P. Phillips, Hastings, Mich., assignor toHastings Manufacturing Company, Hastings,

Mich.

Application January 6, 1947, Serial No. 720,462

3 Claims.

This invention relates to improvements in a cylinder broach.

The principal objects of this invention are:

First, to provide a broach for refinishing the cylinder walls of aninternal combustion engine which may be used while the engine is mountedin an automobile and without remov ing the crank shaft from the engine.1

Second, to provide a broach for refinishing the cylinders of anautomobile engine which can be used on all cylinders of the engine whilethe engine is installed in the body of the automobile regardless ofoverhanging body parts, particularly over the rear cylinder of theengine.

Third, to provide a power driven broach for refinishing the cylinders ofan automobile engine to which power may be applied by a convenient powertool such as an electric drill applied horizontally over the top of thecylinder block.

Fourth, to provide a modified form of broach for refinishing thecylinders of an automobile engine in which power for operating thebroach is supplied by a conveniently operated fluid pressure cylinder.

Fifth, to provide a self centering broach for refinishing the cylinderwalls of an internal combustion engine which requires relatively littleclearance at the ends of the cylinders for installation and operation.

Other objects and advantages pertaining to the details and economies ofthe invention will be apparent from the following description andclaims.

The drawings, of which there are two sheets, illustrate a preferred andone modified form of my broach as applied to the engine ofanwautomobile, certain of the parts of the automobile being illustratedconventionally.

Fig. 1 is a fragmentary plan View of the cylinder block of an automobileengine with my broach in operative position thereon.

Fig. 2 is a fragmentary side elevational view of the cylinder block andbroach shown in Fig. l, a portion of the cylinder block being brokenaway to illustrate the operation of the broach.

Fig. 3 is a fragmentary vertical longitudinal cross sectional view alongthe line 3-3 in Fig. 1.

Fig. 4 is a fragmentary vertical longitudinal cross sectional viewthrough a modified form of cylinder broach in operative position in therear cylinder of an automobile engine.

Fig. 5 is a fragmentary cross sectional view similar to Fig. 4 butillustrating the broach in partially installed position.

It is a common practice to refinish the cylinder bores of automobileengines after the cylinders have become Worn by prolonged use by passingrotary hones or cutters through the cylinders to refinish the walls intrue cylindrical shape. However, these refinishing tools are large andhave considerable aligning and driving mechanism which must be locatedon top of the cylinder block which usually necessitates the removal ofthe cylinder block from the body of the automobile and the removal ofthe crank shaft from the cylinder block. This is particular- 1y true inautomobiles in which the rear cylinder is positioned underneath anover-hanging portion of the dash panel of the body. My tool is selfcentering and requires very little clearance over the top of thecylinder block for installation and the application of power to thebroach. The broach is further operative without removing the crank shaftfrom the engine so that the refinishing operation may be easilyaccomplished without removing the crank shaft from the engine.

The drawings illustrate the cylinder block i of an automobile engineprovided with the usual cylinders 2 and mounted in an automobile havingan overhanging dash panel 3 which is positioned over the rear cylinderof the cylinder block. My refinishing tool consists of a downwardlyopening cylindrical support 4 which is arranged to rest on the top ofthe cylinder block surrounding the upper end of the cylinder 2. The endwall of the support 4 is apertured to pass a guide bar 5 having screwthreads 5 formed thereon. The guide bar 5 extends upwardly through agear plate I secured to the end wall of the support. The bar is pinconnected to a gear 8 clamped against axial movement on the bar by thenut 53. A bushing I0 is provided around'the guide bar 5 where it passesthrough the gear plate.

The gear plate I is provided with a pair of upstanding ears I I whichare apertured to rotatably support a drive shaft l2 having a worm gear13 thereon. The worm gear I3 is in driving engagement with the gear 8 onthe end of the guide bar. The end of the drive shaft I2 is provided witha bayonet type coupling i l for receiving the end of a driving tool suchas an electric drill. The total height of the support and gear plateincluding the upper end of the guide bar 5 and the drive shaft i2 isrelatively short permitting easy installation of the support below theoverhanging portion 3 of the dash panel. The drive shaft I2 extendshorizontally over the top of the cylinder block so that the driving toolmay be applied thereto without interference from the overhanging dashpanel. The support and gear plate are operative in any horizontalposition relative to the axis of the cylinder so the drive shaft I2 mayassume any convenient position for attachment of the power tool.

Positioned around the guide bar and threadedly engaging the threads 6 isa broach I5 having a series of longitudinally spaced annular cuttingedges I6 formed around the outside thereof. A centering disk I! ispositioned around the guide bar 5 between the top of the broach and theunderside of the support member 4. The centering disk IT is arranged toslide along the guide bar 5 and is provided with a beveled surfaceengageable with the upper end of the cylinder bore for centering theguide bar and the support 4 with respect to the walls of the cylinder 2.

The guide bar 5 and threads 6 are of such a length as to extend belowthe bottom of the cylinder bore 2, a distance equal to the length of thebroach I5 permitting the broach to be screwed on the lower end of theguide by hand below the engine block. The guide bar 5 is passeddownwardly through the cylinder bore 2 until the support 4 engages thetop of the cylinder block and the centering disk I? engages the upperend of the cylinder bore to center the guide bar and the support aboutthe axis of the cylinder bore. The broach I 5 is then threaded on thelower end of the guide bar 5 until its upper cutting edge 6 engages thebottom of the cylinder bore at which time the annular cutting edge willhave a self-centering action in the cylinder bore so that the guide bar5 is properly aligned in the cylinder bore by the centering disk I! andthe upper cutting edge of the broach I5. A power tool such as anelectric drill may then be applied to the bayonet coupling I4 to rotatethe drive shaft and worm gear which in turn drive the gear 8 and guiderod 5. The threaded connection between the threads 6 and broach I5 willcause the broach to be drawn upwardly through the cylinder bore makingthe required cut from the cylinder walls as it moves axially along theguide bar. Initially the broach I5 may be held against rotation with theguide bar by grasping the broach below the cylinder block. As the broachtravels into the cylinder bore friction between the cutting edges I6 andthe walls of the cylinder bore will prevent rotation of the broach sothat rotation of the guide bar 5 causes simple axial motion of thebroach through the cylinder bore. The cylindrical support 4 is of suchheight as to permit the broach I5 to be drawn completely into thesupport carrying the centering disk H with it as it approaches the topof its travel. (See Fig. 3.)

The axially spaced cutting edges I6 form a self-aligning engagement withthe walls of the cylinder bore and the centering disk I I maintains theupper end of the guide bar centered in the cylinder bore until the finalmovement of the broach out of the cylinder bore. Thus the tool may beeasily used on any of the cylinders of the cylinder block including therear cylinder underneath the overhanging portion of the dash panel.Broaches of difierent diameter will of course be used depending on thediameter of cylinder being broached.

A modified form of broach illustrated in Figs. 4 and 5 is provided witha sectional guide bar having an upper section I 8 threadedly connectedwith the end wall of the downwardly opening cylindrical support I9 whichis engageable with the top of the cylinder block I. The lower end of theupper section I8 is provided with a tapped aperture for receiving thethreaded upper end of the lower section 26 of the guide bar. The lowersection is flattened as at Al so that a wrench may be easily appliedthereto for clamping the two sections of the guide bar together. Thelower section 20 extends downwardly through the cover plate 22 of afluid pressure cylinder 23 and is threadedly connected to the bottomwall of the cylinder as at 24.

The pressure cylinder 23 is provided with a piston 25 sealed to thewalls of the cylinder by piston rings 25 and bearing against the lowerend of a tubular ram 21 which extends upwardly through the cover plate22 and around the lower section 20 of the guide bar. The upper end ofthe ram 2'! is arranged to bear against the bottom of the broach I5Awhich is the same as in the preferred form of cylinder broach except fora smooth central bore. A centering disk I1 is provided around the uppersection It of the guide bar as in the first form of the invention.

The lower end of the pressure cylinder 23 is provided with a fluid inletcontrolled by the valve 28 and an outlet controlled by the valve 29 sothat fluid under pressure form a suitable pump, not shown, may beadmitted to the cylinder to raise the piston 25 and the ram 2'1. As inthe first form of the invention the centering disk I! will center theupper end of the guide bar in the cylinder bore and the broach I5 willfunction to center the guide bar in the lower end of the cylinder bore.In attaching the tool in the cylinder of an automobile engine, the uppersection I8 of the guide bar is secured to the support I9 and passeddownwardly through the cylinder bore with the centering disk I!positioned around the guide bar and engaging the upper end of thecylinder bore. The lower section 20 of the guide bar may then be graspedand held below the cylinder block as indicated at Fig. 5 and insertedinto the tapped aperture in the end of the upper section and tightenedby application of a wrench to the flattened portion 2I. The broach I5 isconveniently supported around the lower section 25 by the operator'shand while this connection is being made.

It will be noted from Fig. 5 that the lower section 20 of the guide baris of suflicient length so that the pressure cylinder 23 will hang belowthe crank shaft 30 of the engine with the guide rod extending betweenthe crank throws 3| of the crank pin 32 associated with the cylinder tobe broached. Fluid may then be admitted to the cylinderto raise thepiston and ram as previously described to force the broach through thecylinder. Obviously the pressure cylinder must be long enough to providea length of travel of the piston equal to the length of the cylinderwall being broached plus the distance of the pressure cylinder below thecylinder bore.

As in the first form of the invention the hydraulically operated broachmay be easily and quickly applied to any of the cylinders of anautomobile engine without removing the cylinder block from theautomobile and without removing the crank shaft from the cylinder block.Power for operating the pressure cylinder is conveniently supplied tothe cylinder by a pump and flexible conduit, not shown. The time andcost of refinishing the cylinder bores of the engine is thus greatlyreduced.

I have described two highly practical forms of my cylinder broach sothat others may reproduce and operate the same without furtherdescription.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A tool for surfacing a cylinder bore of an engine comprising achambered support member adapted to seat against an engine around acylinder bore and having an inwardly facing recess therein of a diameterexceeding that of the cylinder bore, a guide on said support adapted tobe positioned centrally through the cylinder bore, a centering diskslidable on said guide and engageable within the bore adjacent thesupport to center the guide therein, and a broach translatable alongsaid guide and into said recess in said support.

2. A broaching tool for a cylinder bore of an engine comprising anarched support member adapted to be seated upon the engine at one end ofthe cylinder bore thereof, a centering guide on said support adapted tobe positioned centrally through the cylinder bore, a 25 centering memberslidable on said guide and adapted to seat in the end of the cylinderbore "Table with the bore to center the guide therein,

-.-{"and a broach translatable along said guide.

" HAROLD P. PHILLIPS.

REFERENCES CITED 15 The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date Re. 15,916 Flinchbaugh Sept. 16,1924 136,338 Sanford Feb. 25, 1373 200,071 Love Feb. 5, 1878 576,291Uhelacker Feb. 2, 1897 1 916,134 Fischback Mar. 23, 1909 1,394,079 FuchsOct. 18, 1921 1,434,711 La Pointe Nov. '7, 1922 '--;2,320,'750 RaicheJune 1, 1943

